Thermostat



United States Patent THERMOSTAT John S. Freismuth, St. Clair Shores, Mich., assignor, by mesne assignments, to American Radiator & Standard Sanitary Corporation, New York, N.Y., a corporation of Delaware Application September 13, 1956, Serial No. 609,739

Claims. (Cl. 236--34) 'at right angles to the direction of fluid flow so as to operate uninfluenced by and independent of fluid pressure variations or pressure differences as might be caused by dilferent operating conditions.

(3) The thermostat is of such design as to be quickly responsive to fluid temperature changes.

(4) The thermostat includes a seal which tends to have an increased sealing action at elevated fluid pressures.

(5) The thermostat is of such design as to be free of such frictional forces as might interfere with its successful operation.

Other objects of this invention will appear in the fol lowing description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

Fig. l is a sectional view through one embodiment of the invention.

Fig. 2 is a sectional view on line 22 in Fig. 1.

Fig. 3 is a sectional view taken in the same direction as Fig. l, but showing one portion of a second embodiment of the invention.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

In Fig. 1 there is shown a portion of a cooling water jacket for an internal combustion engine. A fitting 12 is suitably bolted on the outlet face 14 of jacket 10. Face 14 is annularly recessed at 16 for reception of a gasket 18; and the adjacent face of fitting 12 is annularly recessed to accommodate annular wall portions 20 and 22 which are formed integrally with cup element 24.

Element 24 includes a cylindrical side wall 26 having a series of openings 28 formed therein. Element 24 also includes an end wall 30 having its central portion downwardly recessed, as at 32. Facing cup 24 is a second cup 36, which has its side wall 38 slidably telescoped within side wall 26 of cup 24. At low fluid temperatures the free edge 40 of wall 38 seats against portion 42 of wall 30 so as to prevent fluid flow through openings 28. At high fluid temperatures cup 36 is moved in the arrow 44 direction so as to permit fluid flow through openings 28.

In order to move cup 36 there is provided a temperature responsive means 46' which may be constructed as shown in US. Patent No. 2,636,776. Temperature responsive means 46 preferably includes a two piece container 48 which houses a thermally expansible material 50 and a piston 52. The free end of piston 52 threadedly receives a collar 54 which extends through end wall 58 of cup 36. A nut 60 fixedly retains end wall 58 on collar 54. Collar 54 includes an annular flange 62 whichserves to fixedly retain the endmost convolution 64 of a tension spring 66 against the lower face of wall 58. The opposite end 72 of tension spring 66 is fixedly retained on wall 30 by an annular element 68 and rivets an annular deformable sealing member 76 of rubber or.

similar material. Member 76 is positioned within an annular retainer member 78 which is press fit into the recess defined by walls 20 and 22. In order to easily replace member 76 in the event of seal failure, there areprovided in wall 22 a series of knockout openings 80. The sealing action of member 76 against wall 38 is enhanced by providing a groove 82 in its lower face. Groove 82 causes the fluid pressure on member 76 to be directed radially inward as indicated by arrow 84; as a result any increase in fluid pressure tends to increase the sealing action of member 76 against wall 38.

Operation of the Fig. l thermostat is such that ambient fluid flowing in the arrow 86 direction causes material 50 to expand or contract in accordance with the ambient fluid temperature. If the ambient fluid should be at a relatively low temperature cup 36 takes its illustrated position. If the ambient fluid should be at a relatively high temperature material 50 will expandso as to push piston 52 in the arrow 44 direction; cup 36 is thereby moved upwardly so as to allow the ambient fluid to flow through openings 28, into the space within cup 36,

through openings 88 in end Wall 58, and out through passage 90 in fitting 12.

It will be noted that wall 38 moves at right angles to the fluid as said fluid passes through openings 28. As a result the only fluid force tending to prevent wall 38 from closing against seating surface 42 is that fluid force which is directed against edge 40. Due to the relatively small area of edge 40 the fluid force thereon is relatively small; consequently spring 66 can be of relatively light construction and still perform the function of returning cup 36 to its illustrated position on fluid temperature decrease.

A relatively light spring construction is advantageous in that it enables the component parts of the thermostat to be constructed of relatively low-strength, low-cost materials. In this connection it will be understood that spring 66 works against the expansive action of material 50; therefore if spring 66 were of relatively stiff construction the side walls of container 48 would necessarily have to be relatively thick in order to withstand the forces developed by the opposed working action of the spring and material 50.

One advantage of the aforementioned low opening Patented Dec. 29, 1959- force on wall38 feature is that cup 36 can thereby move very quickly in response to fluid temperature decrease, it being appreciated that the fluid pressure is not effective to control the position of member 36. In many prior art thermostats the fluid pressures tend to prevent quick closing ofthe thermostat when the fluid temperature de creases. Withthe present construction the thermostatoperation is-independent of fluid pressure variations such as might occur throughout portions of the operating cycle or as might occur in difierent installations.

The Fig. 3 construction is similar to the Fig. 1 construction except that in the Fig. 3 construction a series of openings 90 are formed in side wall 38. When openings 90 move into partial or full registry with openings 28 fluidis allowed to flow into cup 36. The operationofthe Fig. 3 embodiment is the same as the operation of the Fig. l embodiment, and hence a detailed description thereof at this point is believed to be unnecessary.

I claim:

1. In an engine cooling system, wall means forming a passageway for engine cooling fluid; a first cup positioned in said passageway with its end wall upstream from its side wall; said'end wall being imperforate to prevent fluid flow therethrough; an inlet opening in said cup side wall; a second cup facing said first cup and slidably tele scoped therewithin; an outlet opening in the end wall of the second cup; a container positioned on the upstream face of the first cup end wall; a guide sleeve carried by said container and extending through said first cup end Wall into the space within the second cup; a piston slidably carried in said guide sleeve and rigidly connected to said second cup end wall; thermally expansible material within said container; piston-return means within the second cup; whereby (1) on fluid temperature increase the second cup is forced away from the first cup in such manner that the second cup side wall opens the inlet opening to the space within the second cup, and (2) on temperature decrease the second cup is moved into the first cup in such manner that the second cup side wall closes the inlet opening to the space within the second cup; an annular portion of'the first cup being bent radially outward and then axially away from the first cup end wall to define an annular recess; an annular retainer member of- L-shaped' cross section removably seated in the recess with one leg of the L in facial engagement with the axially directed wall portion and with the other leg of the L in spaced parallelism with the radially directed wall portion; and an annular deformable sealing member seated inthe recess between the parallel walls.

2. The combination of claim 1 wherein the sealing member has an annular groove in the portion thereof facing the. radially: directed wall portion; whereby fluid pressures tend to force the inner portion of the sealing member toward the inner cup so as to enhance the sealing action.

3. The combination of claim 1 wherein the radially directed wall portion is provided with a series of knockout holes for facilitatingremoval of the sealing member.

4. A thermostat comprising a cup having an inlet opening in its side wall; a tubular valve member slidably telescoped within said cup; an annular portion on the cup side wall being bent radially outward and then axially away from the cup end wall to define an annular recess; an annular deformable sealing member seated in said recess in peripheral sealing engagement with the outer surface of the tubular valve element; an annular retainer member removably seated in the recess for retention of the sealing member'therein; said sealing member having an annular groove in the portion thereof facing the radially bent Wall portion; temperature responsive means urging the valve element away from the cup end wall on fluid temperature increase; and means acting in opposition to the temperature responsive means for returning the valve element toward the cup end wall on fluid, temperature decrease.

5. A thermostat comprising a cup having an inlet open ing in its side wall; a tubular valve member slidably telescoped within said cup; an annular portion of the cup side wall being bent radially outward and then axially awayfrom the cup end wall to define an annular recess; an annular deformable sealing member removably seated in said recess in peripheral sealing engagement with the outer surface of the tubular valve element; an annular retainer member of L-shaped cross-section removably seated in the recess with one leg of the L in facial engagement with the axially directed wall portion and with the other leg of the L engaged with the downstream face of the sealing member; said sealing member having an annular groove in its upstream face for allowing the fluid pressure to seat the sealing member against the valve element; temperature responsive means urging the valve member away from the cup end wall on temperature increase; and means acting in opposition to the temperature responsive means for returning the valve element toward the cup end wall on fluid temperature decrease.

References Cited in the file of this patent UNITED STATES PATENTS 1,752,116 Smith Mar. 25, 1930 2,396,138 Vernet Mar. 5, 1946 2,575,100 Duey Nov. 13, 1951 2,590,759 Dale et al. Mar. 25, 1952 2,670,933 Bay Mar. 2, 1954 2,710,146 Drapeau June 7,1955 2,754,062 Von Wangenheim July 10, 1956 2,765,983 Mayo Oct. 9, 1956 2,797,873 Woods July 2, 1957 2,810,524 Puster Oct. 22, 1957 FOREIGN PATENTS 710,360 France Apr. 29, 1930 

